Stand height mapping
The necessary condition for calculating water retention area of leaf surface of different types of tree stands is to estimate the phytomass value during the period of its maximum growth. The phytomass value, in its turn, is determined by stand age correlated with height and a bonitet class of the trees.
The tree height was measured by falling shadows with the use of the ratio:
,
where lm - the length of the shadow (mm);
k - scale factor equal to 1/10000 of scale denominator;
n – coefficient of relative shadow length (Danilin I.M., 2003; Sukhikh V.I., 2005).
The length of the shadow for free-standing trees and forest rows was determined on the basis of the aerial imagery plans kept in the archives of the branch of The Federal Service for State Registration, Cadastre and Cartography (Rosreestr) of the Sverdlovsk region. In order to obtain the average stand height, 3-5 heights of ”typical” trees in the forest areas of the studied region were measured. The results of measurements are shown in the picture (Fig. 6).